Unlock instant, AI-driven research and patent intelligence for your innovation.

Method of treatment of radioactive wastewater

a radioactive wastewater and treatment method technology, applied in the direction of radioactive contaminants, separation processes, nuclear engineering, etc., can solve the problems of large amount of process energy, large number of radioactive byproducts, and high equipment costs, and achieve high polishing properties, remove extremely low concentration of radionuclides, and high purity

Inactive Publication Date: 2015-11-26
TSINGHUA UNIV
View PDF4 Cites 7 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The patent describes a method for purifying wastewater by using a two-stage reverse osmosis and continuous electrodeionization process. This method has several technical effects. First, it can remove extremely low concentrations of radionuclide ions from wastewater without the need for additional acid or base. Second, it reduces the yield of radioactive waste by substituting ion exchange resins with continuous electrodeionization membranes, which decreases the amount of solid radioactive waste and reduces the specific activity of the final effluent. Overall, this method improves the efficiency and quality of wastewater purification.

Problems solved by technology

However, the process consumes a large amount of energy, produces a large number of radioactive byproducts, and involves expensive equipment.
Conventionally, the evaporation treatment process runs under harsh environments and thus equipment involved therein tends to corrode.
In addition, the ion exchange process produces radioactive spent resins as byproducts, which increases the difficulty of post-processing.
However, the resins filled in the membrane stack of a continuous electrodeionization unit do not have a strong selectivity for radionuclides, and the concentration of the nuclide ions is 4-5 orders of magnitude lower than that of non-radioactive ions, leading to a low removal efficiency of the nuclide ions.
As a result, the effluent quality cannot meet the specified discharge standards.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0036]Radioactive wastewater to be treated had a radioactivity of 7000 Bq / L and a conductivity of 850 μS / cm. Prior to starting the treatment process, the membrane module was first washed. After the treatment process was completed, the membrane module was on-line washed again by non-radioactive water or water produced by the process with parameters unchanged. The radioactive wastewater was filtered using a cartridge filter or a sand filter, and the effluent was introduced for a primary reverse osmosis. The volume ratio of the permeate to the concentrate from the primary reverse osmosis was 5:1, and the conductivity of the permeate was 40 μS / cm. The permeate was allowed to undergo the secondary reverse osmosis, and the concentrate was introduced to an electrodialysis reversal unit. The volume ratio of the permeate to the concentrate from the secondary reverse osmosis was 5:1. The concentrate returned to the primary reverse osmosis; the radioactivity of the permeate water decreased to ...

example 2

[0039]Radioactive wastewater to be treated had a radioactivity of 7000 Bq / L and a conductivity of 850 μS / cm. Prior to starting the treatment process, the membrane module was first washed. After the treatment process was completed, the membrane module was on-line washed again by non-radioactive water or permeate produced by the process with parameters unchanged. The radioactive wastewater was filtered using a cartridge filter or a sand filter, and the effluent was introduced for a primary reverse osmosis. The volume ratio of the permeate to the concentrate from the primary reverse osmosis was 3:1, and the conductivity of the permeate was 30 μS / cm. The permeate was allowed to undergo the secondary reverse osmosis, and the concentrate was introduced to an evaporation unit. The volume ratio of the permeate to the concentrate from the secondary reverse osmosis was 10:1. The concentrate returned to the primary reverse osmosis; the radioactivity of the permeate decreased to 100 Bq / L and th...

example 3

[0042]Radioactive wastewater to be treated had a radioactivity of 5000 Bq / L and a conductivity of 1500 μS / cm. Prior to starting the treatment process, the membrane module was first washed. After the treatment process was completed, the membrane module was on-line washed again by non-radioactive water or permeate produced by the process with parameters unchanged. The radioactive wastewater was filtered using a cartridge filter or a sand filter, and the effluent was introduced for a primary reverse osmosis. The volume ratio of the permeate to the concentrate from the primary reverse osmosis was 10:1, and the conductivity of the permeate was 100 μS / cm. The permeate was allowed to undergo the secondary reverse osmosis, and the concentrate was introduced to an evaporation unit. The volume ratio of the permeate to the concentrate from the secondary reverse osmosis was 5:1. The concentrate returned to the primary reverse osmosis; the radioactivity of the permeate decreased to 100 Bq / L and ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A method of treatment of radioactive wastewater. The method includes: allowing radioactive wastewater to undergo reverse osmosis treatment and continuous electrodeionization treatment in sequence. The continuous electrodeionization treatment is carried out in a continuous electrodeionization unit including a continuous electrodeionization membrane stack including a dilute chamber and a concentrate chamber. The dilute chamber is filled with between 30 and 60 vol. % of a first strong-acid cation exchange resin, between 40 and 60 vol. % of a first strong-base anion exchange resin, and between 0 and 30 vol. % of a weak-base anion exchange resin. The concentrate chamber is filled with between 20 and 50 vol. % of a second strong-acid cation exchange resin, and the rest is a second strong-base anion exchange resin.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation-in-part of International Patent Application No. PCT / CN2013 / 088178 with an international filing date of Nov. 29, 2013, designating the United States, now pending, and further claims priority benefits to Chinese Patent Application No. 201310103374.1 filed Mar. 28, 2013. The contents of all of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference. Inquiries from the public to applicants or assignees concerning this document or the related applications should be directed to: Matthias Scholl P. C., Attn.: Dr. Matthias Scholl Esq., 245 First Street, 18th Floor, Cambridge, Mass. 02142.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The invention relates to a method of treatment of radioactive wastewater.[0004]2. Description of the Related Art[0005]Typically, radioactive wastewater is treated by evaporation and ion exchange. However, t...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): C02F1/44C02F1/469
CPCC02F1/441C02F2201/46115C02F2101/006C02F1/4695B01D61/025B01D61/48B01D61/58C02F2001/427G21F9/06G21F9/12Y02A20/124Y02A20/131
Inventor ZHAO, XUANLI, FUZHIZHANG, MENG
Owner TSINGHUA UNIV